#include <bits/stdc++.h>

using namespace std;
int rmq[22][400005];
int E[400005],k;
int niv[400005],poz[100003];
int a[100003],n;
int P[100003];
vector<int>L[100003];
void Euler(int nod,int nivel)
{
    E[++k]=nod;
    niv[k]=nivel;
    poz[nod]=k;
    for(auto i:L[nod])
    {
        Euler(i,nivel+1);
        E[++k]=nod;
        niv[k]=nivel;
    }
}
int main()
{
    int i,j,x,y,N,Q;
    ifstream fin("lca.in");
    ofstream fout("lca.out");
    fin>>n>>Q;
    for(i=2; i<=n; i++)
    {
        fin>>x;
        L[x].push_back(i);
    }
    Euler(1,1);
    ///P
    P[1]=0;
    for(i=2; i<=k; i++)
        P[i]=1+P[i/2];


    ///rmq
    for(i=1; i<=k; i++)
        rmq[0][i]=i;
    N=P[k];
    for(i=1; i<=N; i++)
        for(j=1; j<=k+1-(1<<i); j++)
        {
            x=niv[rmq[i-1][j]];
            y=niv[rmq[i-1][j+(1<<(i-1))]];
            if(x<y)rmq[i][j]=rmq[i-1][j];
            else rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
        }
    ///Q
    while(Q--)
    {
        fin>>x>>y;
        x=poz[x];
        y=poz[y];
        if(x>y)swap(x,y);
        N=P[y-x+1];
        i=rmq[N][x];
        j=rmq[N][y-(1<<N)+1];
        if(niv[i]<niv[j])fout<<E[i]<<"\n";
        else fout<<E[j]<<"\n";
    }
    fout.close();
    return 0;
}